Yes you'll get a criminal record.
In England & Wales your offence will always show up on any criminal records check, whether that be at 'Standard' or 'Enhanced' level. However such checks should only be available to employers (and voluntary organisations) where the work (or voluntary activity) will bring you into contact with children or vulnerable adults (or where national security or the administration of justice is involved).
In Scotland and Northern Ireland similar arrangements apply in regard to 'Standard' or 'Enhanced' checks but ANY employer may require a check at 'Basic' level (which doesn't exist in England & Wales). Your offence will only show up on a 'Basic' check for 5 years from the date of conviction, as it will then be 'spent'. (That assumes that it's dealt with by a fine and that you're not under 18 years old).
In any part of the UK, until your offence becomes 'spent' you must declare it on any form which asks about criminal convictions. (e.g. when applying for employment or for insurance). Thereafter you only need to declare it if the work (or voluntary activity) is exempted from the provisions of the Rehabilitation of Offenders Act:
http://www.lawonthewe...tion_of_Offenders_Act
Other countries don't recognise that Act so, for example, your conviction can never be regarded as 'spent' when seeking to travel to the USA. You will be prohibited from entering under the Visa Waiver Program, so you must go through the tedious process of applying for a visa.
On arrival at the court building you should go the reception desk to let them know that you've arrived. You'll be asked if you'll be entering a plea (and, if so, what it will be). You'll be given a form to fill out, detailing your income and expenditure. (It would help to have those figures ready in advance). Then you'll possibly be hanging around for ages, until an usher (either directly, or via a PA system) calls you into court.
The actual court process will only last a few minutes. (Each magistrate's courtroom typically handles around three dozen routine cases in a single day). You'll be required to stand in the dock and to confirm your name. The charge will read to you and you'll be asked how you wish to plead. Once you've pleaded guilty, the Crown Prosecution Service solicitor will explain the facts of the matter to the bench (which will either consist of three magistrates or one district judge). You will then be invited to have your say. (Keep it simple. Keep it short. Just apologise). The bench will then pass sentence. You can pay the fine, by debit or credit card, using the free phone which is available in the court building. (Or you can pay by post).
Chris